User Manual
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Calibrating the VCO B FINAL OUT
Trims for FINAL OUT are SHAPE Balance (3) which is accessed through the top side of the module and
FOLD Gain (4) which is accessed through the right side of the module. Take care in lifting the module out of
case for calibration.
1. Before this calibration may be performed, the SINE Shape and Amplitude calibration must be completed.
2. Monitor the VCO B FINAL OUT (2) and view the signal on an oscilloscope set for 2V/ div. by 2ms/ div.
3. Set VCO B to be near to frequency of C4.
4. Make the following setting in the Timbre section:
FOLD parameter to around 25% so you are able to see a sine wave on the oscilloscope.
ANGLE parameter set to around 50% so the waveform is symmetrical.
SHAPE parameter to 100%, take note of the "maximum shape," after the calibration this same
shape should form with SHAPE set to 100%. Now set SHAPE to 50%.
5. Adjust SHAPE trim (3) so the sine shape is minimized, and the waveform is a SPIKE.
6. Set SHAPE to 100% and check that the "maximum shape" waveform appears as it did at end of step 4. If
not, adjust SHAPE trim (3) minimally, splitting the difference between the optimal maximum setting
and the optimal SPIKE setting.
7. Return SHAPE to 0%.
8. Slowly turn FOLD to 100% counting 5 folds in the waveform. With FOLD at 100% take note of the widest
portion of the waveform. This is the Fundamental Fold.
9. Turn FOLD gain CW until the widest portion of the waveform stops increasing in width.
10. Turn FOLD CCW down to 50% counting the unfolding. The last two folds (4 and 5) should come undone
by around 50% of the FOLD parameter. If not, then adjust FOLD Gain trim (5) for the optimal setting,
splitting the difference between the widest fundamental fold, and complete unfolding of last two folds
at 50% FOLD setting. If needed, Amplitude of VCO B SINE might require adjustment as well in order
to make all 5 folds occur (increase amplitude) or to meet the requirement of unnfolding the last two
folds by the 50% parameter value (decrease amplitude). The most important thing is that the FOLD
circuit sounds good though, so give it a listen.